Naming ability changes in physiological and pathological aging

Decreased Facial Emotion Recognition in Elderly Patients With Hearing Loss Reflects Diminished Social Cognition

OBJECTIVE

The main objective of this research was to evaluate the correlation between the severity of hearing loss and the facial emotional recognition as a critical part of social cognition in elderly patients.

METHODS

The prospective study was comprised of 85 individuals. The participants were divided into 3 groups. The first group consisted of 30 subjects older than 65 years with a bilateral pure-tone average mean >30 dB HL. The second group consisted of 30 subjects older than 65 years with a PTA mean ≤30 dB HL. The third group consisted of 25 healthy subjects with ages ranging between 18 and 45 years and a PTA mean ≤25 dB HL. A Facial Emotion Identification Test and a Facial Emotion Discrimination Test were administered to all groups.

RESULTS

Elderly subjects with hearing loss performed significantly worse than the other 2 groups on the facial emotion identification and discrimination tests (P < .05). Appealingly, they identified a positive emotion, "happiness," more accurately in comparison to the other negative emotions.

CONCLUSIONS

Our results suggest that increased age might be associated with decreased facial emotion identification and discrimination scores, which could be deteriorated in the presence of significant hearing loss.

Effects of concurrent action and object naming treatment on naming skills and functional brain activation patterns in primary progressive aphasia: An fMRI study with a case-series design

Individuals with primary progressive aphasia (PPA) exhibit differential impairment patterns in noun and verb naming, but it remains unclear whether anomia treatment results in similar improvements in noun and verb naming. Therefore, we examined the immediate and long-term (3-months post-treatment) behavioral and neural effects of an anomia treatment on object and action naming skills in PPA. A case-series design was utilized involving two individuals with PPA. Object and action words were trained concurrently and probed regularly using word lists matched on a number of lexical characteristics. One participant showed improvements in all word categories with different effect sizes whereas the other participant demonstrated improved naming only on trained object words. Treatment-induced fMRI changes were found in both hemispheres, with distinct patterns observed across participants. Further research is needed to better understand the effects of residual language and cognitive skills on behavioral and neurophysiological outcomes following anomia treatment for PPA.

Intensive naming training for low-educated demented and non-demented elderly

ABSTRACT. Complaints about naming difficulties may be common in the elderly. In dementia, anomia is the most frequent symptom of language disorders. Naming training can improve lexical access and promote better quality of communication for elderly with or without dementia. Objective: To analyze naming scores, response time and the generalization of responses for naming of neurotypical and demented low-educated older adults before and after receiving a naming training program, with and without oral comprehension stimulation. Method: Twenty elderly participants, 10 with dementia and 10 neurotypical, were included after interview, screening for cognition and functionality. The naming training was based on retrieval practice and carried out in 5 sessions. Half of the group underwent exclusive naming training, while the other half received naming training associated with oral comprehension stimulation. Results: Elderly people with dementia performed better after training for scores on oral naming and comprehension of oral words, except for object manipulation. The response time for naming trained and untrained stimuli was also better for elderly people with dementia. After the intervention, neurotypical individuals performed statistically better in comprehension time and in the score in oral naming, comprehension of oral words and object manipulation, for trained and untrained words. Conclusion: Naming training, exclusive or associated with oral comprehension, using the recovery technique benefits the language performance of neurotypical and demented elderly, and provides improvements even for untrained stimuli.

Diagnostic Value of Time-Constrained Naming Test in Mild Cognitive Impairment

BACKGROUND

Naming difficulties have recently garnered more interest in elderly individuals with mild cognitive impairment (MCI). We anticipate that naming tests with the consideration of response time can provide more informative and distinct neuropsychological profiles of individuals with MCI.

METHODS

Naming tests were administered to 76 elderly individuals with MCI and 149 healthy elderly (HE). We analyzed the impact of MCI on naming performance and occurrence of "delayed" response. We also validated the predictive power of naming tests with a time-constrained scoring system.

RESULTS

MCI participants performed poorer on the noun naming test than HE participants (p = 0.014). MCI was significantly associated with the occurrence of "delayed" response on the noun (odds ratio [OR] = 3.57; 95% confidence interval [CI] = 1.78-7.17) and verb naming tests (OR = 4.66; 95% CI = 2.07-10.46). The time-constrained naming scores were significantly better able to distinguish the MCI from the HE group than the conventional spontaneous naming score on both the noun (p < 0.001) and verb (p = 0.002) naming tests.

CONCLUSIONS

Our findings broaden the knowledge related to the naming ability in individuals with MCI, with respect to the response time. We also confirmed the validity of the naming tests by applying the "delayed" responses as supplementary assessments in the diagnosis of MCI.

Designing in vitro Blood-Brain Barrier Models Reproducing Alterations in Brain Aging

Blood-brain barrier (BBB) modeling in vitro is a huge area of research covering study of intercellular communications and development of BBB, establishment of specific properties that provide controlled permeability of the barrier. Current approaches in designing new BBB models include development of new (bio) scaffolds supporting barriergenesis/angiogenesis and BBB integrity; use of methods enabling modulation of BBB permeability; application of modern analytical techniques for screening the transfer of metabolites, bio-macromolecules, selected drug candidates and drug delivery systems; establishment of 3D models; application of microfluidic technologies; reconstruction of microphysiological systems with the barrier constituents. Acceptance of idea that BBB in vitro models should resemble real functional activity of the barrier in different periods of ontogenesis and in different (patho) physiological conditions leads to proposal that establishment of BBB in vitro model with alterations specific for aging brain is one of current challenges in neurosciences and bioengineering. Vascular dysfunction in the aging brain often associates with leaky BBB, alterations in perivascular microenvironment, neuroinflammation, perturbed neuronal and astroglial activity within the neurovascular unit, impairments in neurogenic niches where microvascular scaffold plays a key regulatory role. The review article is focused on aging-related alterations in BBB and current approaches to development of “aging” BBB models in vitro.

The role of the motor system in action naming in patients with neurodegenerative extrapyramidal syndromes

Previous studies of patients with brain damage have suggested a close relationship between aphasia and movement disorders. Neurodegenerative extrapyramidal syndromes associated with cognitive impairment provide an interesting model for studying the neural substrates of cognitive and motor symptoms. In this review, we focused on studies investigating language production abilities in patients with Parkinson's disease (PD), Corticobasal Syndrome (CBS) and Progressive Supranuclear Palsy (PSP). According to some reports, these patients exhibit a reduction in performance in both action and object naming or verb production compared to healthy individuals. Furthermore, a disproportional impairment of action naming compared to object naming was systematically observed in patients with these disorders. The study of these clinical conditions offers the unique opportunity to examine the close link between linguistic features and motor characteristics of action. This particular pattern of language impairment may contribute to the debate on embodiment theory and on the involvement of the basal ganglia in language and in integrating language and movement. From a translational perspective, we suggest that language ability assessments are useful in the clinical work-up, along with neuropsychological and motor evaluations. Specific protocols should be developed in the near future to better characterize language deficits and to permit an early cognitive diagnosis. Moreover, the link between language deficits and motor impairment opens a new issue for treatment approaches. Treatment of one of these two symptoms may ameliorate the other, and treating both may produce a greater improvement in patients' global clinical conditions.

Functional MRI evidence for the decline of word retrieval and generation during normal aging

This fMRI study aimed to explore the effect of normal aging on word retrieval and generation. The question addressed is whether lexical production decline is determined by a direct mechanism, which concerns the language operations or is rather indirectly induced by a decline of executive functions. Indeed, the main hypothesis was that normal aging does not induce loss of lexical knowledge, but there is only a general slowdown in retrieval mechanisms involved in lexical processing, due to possible decline of the executive functions. We used three tasks (verbal fluency, object naming, and semantic categorization). Two groups of participants were tested (Young, Y and Aged, A), without cognitive and psychiatric impairment and showing similar levels of vocabulary. Neuropsychological testing revealed that older participants had lower executive function scores, longer processing speeds, and tended to have lower verbal fluency scores. Additionally, older participants showed higher scores for verbal automatisms and overlearned information. In terms of behavioral data, older participants performed as accurate as younger adults, but they were significantly slower for the semantic categorization and were less fluent for verbal fluency task. Functional MRI analyses suggested that older adults did not simply activate fewer brain regions involved in word production, but they actually showed an atypical pattern of activation. Significant correlations between the BOLD (Blood Oxygen Level Dependent) signal of aging-related (A > Y) regions and cognitive scores suggested that this atypical pattern of the activation may reveal several compensatory mechanisms (a) to overcome the slowdown in retrieval, due to the decline of executive functions and processing speed and (b) to inhibit verbal automatic processes. The BOLD signal measured in some other aging-dependent regions did not correlate with the behavioral and neuropsychological scores, and the overactivation of these uncorrelated regions would simply reveal dedifferentiation that occurs with aging. Altogether, our results suggest that normal aging is associated with a more difficult access to lexico-semantic operations and representations by a slowdown in executive functions, without any conceptual loss.

Modulation of the inter-hemispheric processing of semantic information during normal aging. A divided visual field experiment

We evaluated the effect of normal aging on the inter-hemispheric processing of semantic information by using the divided visual field (DVF) method, with words and pictures. Two main theoretical models have been considered, (a) the HAROLD model which posits that aging is associated with supplementary recruitment of the right hemisphere (RH) and decreased hemispheric specialization, and (b) the RH decline theory, which assumes that the RH becomes less efficient with aging, associated with increased LH specialization. Two groups of subjects were examined, a Young Group (YG) and an Old Group (OG), while participants performed a semantic categorization task (living vs. non-living) in words and pictures. The DVF was realized in two steps: (a) unilateral DVF presentation with stimuli presented separately in each visual field, left or right, allowing for their initial processing by only one hemisphere, right or left, respectively; (b) bilateral DVF presentation (BVF) with stimuli presented simultaneously in both visual fields, followed by their processing by both hemispheres. These two types of presentation permitted the evaluation of two main characteristics of the inter-hemispheric processing of information, the hemispheric specialization (HS) and the inter-hemispheric cooperation (IHC). Moreover, the BVF allowed determining the driver-hemisphere for processing information presented in BVF. Results obtained in OG indicated that: (a) semantic categorization was performed as accurately as YG, even if more slowly, (b) a non-semantic RH decline was observed, and (c) the LH controls the semantic processing during the BVF, suggesting an increased role of the LH in aging. However, despite the stronger involvement of the LH in OG, the RH is not completely devoid of semantic abilities. As discussed in the paper, neither the HAROLD nor the RH decline does fully explain this pattern of results. We rather suggest that the effect of aging on the hemispheric specialization and inter-hemispheric cooperation during semantic processing is explained not by only one model, but by an interaction between several complementary mechanisms and models.

The timing of cognitive plasticity in physiological aging: a tDCS study of naming

This study aimed to explore the effects of transcranial direct current stimulation (tDCS) on physiologically aging adults performing a naming task. tDCS is a method that modulates human cortical excitability. Neuroplasticity is considered to have its foundation in cortical excitability as a property that adjusts the connection strength between neurons in the brain. Language efficiency, as all functions, relies on integration of information (i.e., effectiveness of connectivity) through neurons in the brain. So the use of tDCS, to modulate cortical excitability, can help to define the state of cognitive plasticity in the aging brain. Based on Hebb's rule, an increase in synaptic efficacy does not rely only on the increase of excitability but also on the timing of activation. Therefore, a key issue in this study is the timing of tDCS application in relation to a task: When to deliver tDCS to induce modulatory effects on task execution to facilitate naming. Anodal tDCS was applied to the left dorsolateral prefrontal cortex of older and young adults before and during a naming task. In older adults, tDCS improved naming performance and decreased the verbal reaction times only if it was applied during the task execution, whereas in young subjects both stimulation conditions improved naming performance. These findings highlight that in healthy aging adults, the cerebral network dedicated to lexical retrieval processing may be facilitated only if stimulation is applied to an "active" neural network. We hypothesize that this change is due to the neuronal synaptic changes, in the aging brain, which reduce the window of when cortical excitability can facilitate synaptic efficacy and therefore plasticity.

Subjective word-finding difficulty reduces engagement in social leisure activities in Alzheimer's disease

OBJECTIVES

To assess the influence of subjective word-finding difficulty on degree of engagement in social leisure activities among individuals with Alzheimer's disease (AD).

DESIGN

Analysis of data collected from the second cohort of the Multicenter Study of Predictors of Disease Course in Alzheimer's disease.

SETTING

Four study sites in the United States and France.

PARTICIPANTS

Individuals diagnosed with mild to moderate AD (N = 236).

MEASUREMENTS

On separate questionnaires, participants were asked to 1) report whether they had trouble finding the right word when speaking (subjective word-finding difficulty) and 2) rate their frequency and enjoyment of social and nonsocial leisure activities. Objective language measures included object naming and verbal fluency. Measures of dependence, depression, cognitive status, age, sex, and education were also included as covariates in regression analyses.

RESULTS

Fifty-two percent of the sample reported word-finding difficulty, and subjective complaints were correlated with poorer verbal fluency scores. Subjective word-finding difficulty was selectively related to social but not nonsocial activity measures. Endorsers of word-finding difficulty reported less frequency and enjoyment of social leisure activities, controlling for effects of covariates and objective word-finding ability. In contrast, lower engagement in nonsocial activities was associated with older age and higher depression scores but not with word-finding complaints. Caregivers' reports of study participants' activities corroborated these results.

CONCLUSION

Individuals with AD who are aware of increasing word-finding failures are less likely to participate in and enjoy socially oriented leisure activities. This finding may have significant implications for clinical and health outcomes in AD. Failure to evaluate subjective language complaints could result in social withdrawal symptoms, threatening the individual's quality of life and increasing caregiver burden. Reduced social interaction may ultimately exacerbate language symptoms over time.

Beneficial effects of multisensory and cognitive stimulation on age-related cognitive decline in long-term-care institutions

The aim of the present report was to evaluate the effectiveness and impact of multisensory and cognitive stimulation on improving cognition in elderly persons living in long-term-care institutions (institutionalized [I]) or in communities with their families (noninstitutionalized [NI]). We compared neuropsychological performance using language and Mini-Mental State Examination (MMSE) test scores before and after 24 and 48 stimulation sessions. The two groups were matched by age and years of schooling. Small groups of ten or fewer volunteers underwent the stimulation program, twice a week, over 6 months (48 sessions in total). Sessions were based on language and memory exercises, as well as visual, olfactory, auditory, and ludic stimulation, including music, singing, and dance. Both groups were assessed at the beginning (before stimulation), in the middle (after 24 sessions), and at the end (after 48 sessions) of the stimulation program. Although the NI group showed higher performance in all tasks in all time windows compared with I subjects, both groups improved their performance after stimulation. In addition, the improvement was significantly higher in the I group than the NI group. Language tests seem to be more efficient than the MMSE to detect early changes in cognitive status. The results suggest the impoverished environment of long-term-care institutions may contribute to lower cognitive scores before stimulation and the higher improvement rate of this group after stimulation. In conclusion, language tests should be routinely adopted in the neuropsychological assessment of elderly subjects, and long-term-care institutions need to include regular sensorimotor, social, and cognitive stimulation as a public health policy for elderly persons.

Enhancing verbal episodic memory in older and young subjects after non-invasive brain stimulation

Memory is the capacity to store, maintain, and retrieve events or information from the mind. Difficulties in verbal episodic memory commonly occur in healthy aging. In this paper, we assess the hypothesis that anodal transcranial direct current stimulation (tDCS) applied over the dorsolateral prefrontal cortex (DLPFC) or over the parietal cortex (PARC) could facilitate verbal episodic memory in a group of 32 healthy older adults and in a group of 32 young subjects relative to a sham stimulation using a single-blind randomized controlled design. Each participant underwent two sessions of anodal tDCS (left and right) and one session of sham stimulation. Overall, our results demonstrated that, in young and in older subjects, anodal tDCS applied during the retrieval phase facilitates verbal episodic memory. In particular, we found that tDCS applied over the left and right regions (DLPFC and PARC) induced better performance in young participants; only tDCS applied over the left regions (DLPFC and PARC) increased retrieval in older subjects. These results suggest that anodal tDCS can be a relevant tool to modulate the long-term episodic memory capacities of young and older subjects.